Objective: To investigate the effect of Sishen Wan on the balance of Treg/Th17 in Payer's patch of colitis rats. Method: The forty SD rats were randomly divided into 4 groups:normal group

model group

Sishen Wan group (2.5 g·kg-1) and mesalazine group (0.15 g·kg-1). Except the normal group

all other groups established the rat colitis models induced by 2

4

6-trinitrobenzene sulfonic acid (TNBS). Drugs were given intragastrically for 7 days. The levels of T lymphocyte subsets were measured by flow cytometry

and the ratio of Treg/Th17 was then calculated. The expressions of retinoid acid-related orphan receptor γt (ROR-γt) and signal transducer and activator of transcription 5a (STAT5a) were tested by the Western blot. Result: Compared with the normal group

the model group significantly increased the levels of CD4+T lymphocyte

significantly decreased CD8+T cells

significantly increased the ratio of CD4/CD8

significantly decreased CD4+CD25+Foxp3+Treg cells

significantly increased Th17 cells

decreased the ratio of Treg/Th17

increased the expressions of ROR-γt protein in colon tissues

and significantly decreased the expressions of STAT5a protein (P<0.05

P<0.01). Compared with the model group

Sishen Wan group significantly decreased CD4+T lymphocyte in Payer's patch of rats

significantly increased CD8+T cell levels

and significantly decreased the ratio of CD4/CD8 (P<0.01). At the same time

Sishen Wan group significantly increased CD4+CD25+Foxp3+Treg cells

decreased Th17 cells

increased the ratio of Treg/Th17

decreased the expressions of ROR-γt protein in colon tissues

and significantly increased the expressions of STAT5a protein (P<0.05

P<0.01). Conclusion: The Sishen Wan could regulate the T lymphocyte subsets

and by inhibiting the expressions of RORγt and increasing the protein secretion of STAT5a

it can also regulate the balance of Treg/Th17.